This invention relates specifically to combined antihistaminic and mast cell stabilizing compounds, having therapeutic use in various diseases, most importantly for patients suffering from ocular diseases, such as vernal conjunctivitis, keratitis, and mast cell degranulation
The compound described in this invention 10-oxo-4Hbenzo[4,5]cyclohepta[1,2-b]thiophene, hereinafter called norketotifen and the 10-OH-substituted analogs thereof, hereinafter called 10-OH-norketotifen.
The parent compound of norketotifen is ketotifen, which has now been found to be less active as an antihistamine, more sedating, more toxic and more irritating to the eye than norketotifen. ##STR1##
Norketotifen can be metabolized in the body along various pathways. Thus, the two isomers of 10-OH norketotifen are formed by reduction of the norketotifen molecule. Norketotifen and 10-OH norketotifen can also undergo N-glucuronidation. Other metabolites, such as for example 9-OH-norketotifen and 9,10-di-OH-norketotifen may be formed and may as well be therapeutically active entities for the ocular indications of this application. The metabolic pathways are different in different species and may also be different between infants and adult humans.